Influence of surface morphology and UFG on damping and mechanical properties of composite reinforced with spinel MgAl{sub 2}O{sub 4}-SiC core-shell microcomposites

Journal Article · Sun Jan 15 04:00:00 EST 2017 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2016.11.042· OSTI ID:22689695

Singh, Subhash; Pal, Kaushik

Interface between ceramic particulate and matrix is known to control the response of the materials and functionality of the composite. Among numerous physical properties, grain structure of the materials has also played a significant role in defining the behaviour of metal matrix composites. Usually, silicon carbide (SiC) particles show poor interfacial wettability in aluminium melt. Herein, we were successfully synthesized magnesium oxide (MgO) and nanocrystalline magnesium aluminate (MgAl{sub 2}O{sub 4}) spinel coated silicon carbide (SiC) core-shell micro-composites through sol-gel technique to improve the wettability of dispersoids. Core-shell structures of submicron size were thoroughly investigated by various characterization techniques. Further, aluminium matrix composites incorporated with pristine SiC, MgO grafted SiC and MgAl{sub 2}O{sub 4} grafted SiC particles were fabricated by stir casting technique, respectively. Additionally, as-cast composites were processed via friction stir processing (FSP) technique to observe the influence of grain refinement on mechanical and damping properties. Electron back scattered diffraction (EBSD), Field emission scanning electron microscopy (FE-SEM) and X-ray energy dispersion spectroscopy (EDX) analysis were conducted for investigating grain size refinement, adequate dispersion, stability and de-agglomeration of encapsulated SiC particles in aluminium matrix. The mechanical as well as thermal cyclic (from − 100 to 400 °C) damping performance of the as-cast and friction stir processed composites were studied, respectively. Finally, the enhanced properties were attributable to reduced agglomeration, stabilization and proper dispersion of the tailored SiC particles Al matrix. - Highlights: •Synthesizing a novel coating layer of MgO and MgAl{sub 2}O{sub 4} spinel onto SiC particles •Significant improvement in UTS and hardness by reinforcing tailored SiC in Al •Significant grain refinements were obtained through FSP •SiC/MgAl{sub 2}O{sub 4}/Al exhibits ~ 61% higher storage modulus as compare to pure Al after FSP.

• OSTI ID: 22689695
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 123; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGGLOMERATION
ALUMINIUM
BACKSCATTERING
CASTING
COMPARATIVE EVALUATIONS
ELECTRON DIFFRACTION
FIELD EMISSION
GRAIN REFINEMENT
GRAIN SIZE
HARDNESS
INTERNAL FRICTION
MAGNESIUM OXIDES
MORPHOLOGY
NANOSTRUCTURES
PARTICULATES
SCANNING ELECTRON MICROSCOPY
SILICON CARBIDES
SOL-GEL PROCESS
SPINELS
WETTABILITY